Over the last few years, global competition and technological advances have focused much attention on the areas of additive manufacturing, 3D printing, smart manufacturing and the like. What has often been neglected are the advancements on a different kind of manufacturing, one where the production floor is only a few nanometers in height. In this world, molecular assemblers scurry across a tiny floor to assemble structures with atomic precision – i.e., atom by atom. This is the reality that the famous physicist Richard Feynman hinted at when he talked about a way to “arrange atoms the way that we want.”
The ideas and initial advances in nanometer technology were significantly influenced by Eric Drexler, an MIT graduate best known for his studies in molecular nanotechnology. Unlike conventional chemistry, in which molecules react as a large group, Drexler proposed a method of "mechanosynthesis" in which individual molecules were specifically positioned close together so that stronger chemical attractions could occur in a controlled way. With such atomic precision, atoms could be added or removed from a structure as desired.
In his book – Engines of Creation: The Coming Era of Nanotechnology – Dr. Drexler proposed the concept of nanoscale assemblers that would build copies of themselves and other molecular sized objects with atomic control. From this, a microscopic production line could be created to build larger and more complex structures, even products that connect to today's semiconductor devices.
There are many examples of such production lines in our world today. Recently, scientists have been able to show how tiny autonomous bots could function as intelligent delivery vehicles to cure cancer in mice. It is even possible to fabricate functional DNA nanostructures that include logic gates to deliver and release molecular cargo for medical applications. Other feasible molecular machines include the molecule walker and the smallest nanocar, which has wheels driven by electronic tunneling.
One new area where atomically precise manufacturing (APM) shows great promise is in quantum technologies, where energy levels and quantum tunneling transport are extremely sensitive to single atom dimensions. APM would be an order of magnitude more precise than even today's leading edge e-beam semiconductor lithography techniques.
A few year ago, I had the opportunity to talk with Dr. Eric Drexler about nanotechnology, atomically precise manufacturing and its relationship to current semiconductor lithography approaches. What follows is an edited version of the actual conversation, part of the Linus Pauling Lecture Series.
|Image Source: CEMES - CNRS|